Two stroke piston-controlled engine



Des. '22, 193%. A. LESAGE TWO-STROKE PISTON-CONTROLLED ENGINE OriginalFiled June 8, 1934 Inventor Patented Dec. 22, 1936 UNITED STATES TWOSTROKE PISTON-CONTROLLED ENGINE Alfred Lesage, Schweinfurt, Germany vOriginal application June 8, 1934, Serial No.

729,550, now Patent No. 2,046,392.

Divided and this application October 23, 1935, Serial No. 46,418. In.Germany June 16, 1933 2 Claims.

cation, Serial No. 729,550, filed June 8, 1934, Patent No. 2,046,392,July '7, 1936.

The invention relates to two-stroke piston- 5 controlled engines inwhich the admission and exhaust apertures are disposed at opposite sidesof the engine cylinder, while the channels communicating with theapertures are in their main conduit obliquely directed towards thecylinder head. Further the said channels enter the cylinder in suchangular relation that the scavenging gases will pass the cylinder spacepractically on a helical path and sweep all points of its interior.

The object of the invention is to provide further leading means for thegas stream within the cylinder itself with the aim to increase thescavenging eflfect.

' This object is attained by giving the piston head the shape of a roofthe ridge of which is disposed with respect to the admission anddischarge channels in a preferably acute angle, so that the gases-aredirected not only towards the cylinder head but also deflected laterallyto opposite points of the cylinder wall far of the ports. Anothercharacteristic useful for the smooth flow and reversal of the gas streamis the construction of the cylinder "head dome or root shaped giving theupper part of'the gas stream the desired helical flow.

These and other objects of the invention will appear as the descriptionthereof proceeds and reference may be had to the appended drawing whichillustrates two embodiments of the novel disposition intendedforproducing the said scavenging process. In said drawing, which forms apart of this specification,.

Fig. l by a vertical sectional view of an engine cylinder illustratesthe subject matter of the invention;

Fig. 2 is a vertical sectional view of the cylinder and the piston in aplane turned through 90 about the axis as compared with Fig. l; Fig. 3illustrates a section through the cylinder on the line CD of Fig. 2 andFig. 4 shows a similar cross section of a cylinder the exhaust openingof which is subdi- This application is a division of my priorappliopposite the said duct there is arranged. also in a tangential andslanting direction with respect to the head [3, an. exhaust duct ii. Theaxes of the channels l0 and H are in parallel planes, as for examplerepresented by Fig. 3. 5

Thus the gases flow through the duct l0 tangentially and in an inclineddirection upward towards the cylinder wall l2 at points laterally andabove the exhaust duct H so that the current of gas is deviated towardsthe cylinder 1 head l3 and helically to the midth of the cylinder I2 soas to push the exhaust gases towards the center of the cylinder anddownward towards the exhaust port H disposed diametrically opposite tothe said inlet port I 0. l5

particularly be adapted to the path of flow desired.

The head of the piston is roof-shaped, while the ridge or top Itthereof, as indicated by the dot and dash line in Fig. 3, is suitablydisposed 30 in more or less acute angles with the inlet direction. Onthe inclined surface adjacent to the inlet duct Hi the fresh gases aredeflected upward and laterally, as stated herebefore, but the other sideof the piston head slopes towards the 35 exhaust duct I I; therefore theridge l6 separates the two branches of the current. of gases from eachother.

In the embodiment shown in Fig. 4 the inlet passage is at an acute angleto the ridge of the 40 piston, the position of which is indicated by thedot and dash center line, and the exhaust passage is ofiset with respectto the inlet port, as in Fig. 3, but it is at an acute angle to theinlet passage and is enlarged and subdivided. 45 The 'flow of the gasesin the cylinder also takes place on helical lines but the discharge ofthe exhaust gases is at the same time improved.

Invention claimed- 1. In a two-stroke combustion engine, the combinationwith a roof-headed cylinder, of an inlet passage on one side of thecylinder and an outlet passage formed on the opposite side of thecylinder in staggered relation to the inlet passage, the axes of saidpassages being dis- 5 inlet passage on one side of the cylinder and anoutlet passage formed on the opposite side of the cylinder in staggeredrelation to the inlet pas-' sage, the axes of said passages beingdirected towards the head of the cylinder, a pistonworking in saidcylinder, and roof-shaped guides formed on said piston and disposedtransversely of said passages when the piston is at the end of theexpansion stroke, the ridge of said roofshaped piston head beingdisposed in acute angles with respect to the axis of the inlet passage.

' ALFRED LESAGE'.

